Costs of energy for the operation of plants are a cost factor not to be underestimated, which can, moreover, not be calculated in the long run if fossil fuels are used. Therefore, efforts have already been made in the most different fields to obtain the necessary energy from other alternative sources, such as from a solar system or a combustion plant for renewable resources. However, so far these energy sources were only used for heating fluids, especially water. It is described, for example, in EP 1 705 242 to use solar collectors for covering at least a part of the thermal energy consumption of a brewery plant, specifically for mashing, lautering and/or wort-cooking, but also for cleaning the plant or for operating a sorptive refrigerating plant. The plant is operated with water as heat transfer medium, which simultaneously serves as process water and is stored in a hot-water heat accumulator. However, this plant allows flow temperatures of a maximum of 180° C.
Packaging devices, especially in the form of the known shrinking devices, were so far mainly heated electrically or sporadically also with natural gas. Examples for packaging devices in the form of shrinking devices are disclosed, for example, in DE 35 16 609, DE 35 43 943, EP 1 288 129 or EP 678452. However, packaging systems require a far higher temperature, for example, for heating the air in shrinking devices, as compared to the heating of process water or heating purposes, and they require a more intensive temperature control, which was previously considered non-practicable if energy sources were used that are not or only to a limited extent controllable, which is the case if heat is generated in solar systems or combustion plants.